The present invention relates to a device for assembly by brazing an end cap or cover onto a cylindrical body, said end cover presenting a circular peripheral rim via which said cover is brazed onto a part of one of the end surfaces of the cylindrical body, and to a vacuum cartridge assembled by means of such an assembly device.
One of the problems relating to assembly by brazing parts of different nature in a furnace, such as a ceramic part with a metal part for example, is linked to the appearance of residual stresses in this assembly mainly due to the difference of the coefficients of expansion of the materials to be assembled. These residual stresses can lead to cracking of the assembly in the short or long term.
The document U.S. Pat. No. 4,436,241 describing a vacuum cartridge is known, said vacuum cartridge comprising a cylindrical body made from ceramic closed at its opposite two ends by an end cap made from stainless steel. These two end caps each present the form of a bowl comprising a free circular rim via which rims said covers are both brazed at the end onto an end surface of the cylindrical body.
Reactive brazing procures a strength that is 20% lower than conventional brazing. This type of brazing is therefore more difficult to perform on a cartridge design as described in the above-mentioned patent.